Development of Kalman filter-based Software Receiver for QZSS L6 and Galileo E6-B Signals

To implement precise point positioning (PPP) toward faster convergence and excellent capability without Internet connections, nations are dedicated to the development of augmentation messages for global navigation satellite system (GNSS). The modernized L6 signals which centered at 1278.75 MHz has been available to broadcast the correction information about satellite orbit and clock bias. Currently, the Quasi-Zenith satellite system (QZSS) and Galileo satellite are capable of transmitting the L6 band signals, which provide regional and global augmentation services, respectively. The purpose of this paper is to develop a software receiver based on Kalman filter carrier tracking architecture for the two constellations. The phase lock loop (PLL) is replaced by a extended Kalman filter (EKF) that has the potential to outperform the conventional loop in certain environments. The low-cost front-end, Pocket SDR are employed to conduct the experiments and analysis. The result shows that the performance of Kalman filter-based tracking loop is comparable with the standard PLL. The phase lock indicator (PLI) is estimated and indicates high performance with low carrier tracking error.